The investigators have developed a modified Spearman estimator for a location or scale parameter for use in small-sample bioassay (dose-response experimentation), and have made a detailed study of application of this estimator to problems where the probability model is exponential, a case in serial-dilution experiments. The proposed research will extend this previous work to provide hypothesis tests and confidence intervals for a location or scale parameter, and to provide estimators for problems in which both location and scale parameters are unknown. Small-sample properties of the methods derived will be studied using a computer, and a comparison made with similar methods based on maximum likelihood estimators. Specific applications will be formulated for problems involving the exponential, normal and logistic probability models, which are the most commonly used in practice. The statistical techniques produced will be in a form directly usuable by biomedical research workers who are not specialists in statistics. Standard methodology of statistical theory and computation will be employed throughout the project.